Straight bar knitting machines



Nov. 20, 1956 E. START 2,770,959

STRAIGHT BAR KNITTING MACHINES Filed April 24, 1953 2 Sheets-Sheet 1 Inventor ERNEST START Nov. 20, 1956 E. START 2,770,959

STRAIGHT BAR KNITTING MACHINES Filed April 24; 1953 2 Sheets-Sheet 2 Inventor fmvesv- 171K? United States Patent STRAIGHT BAR KNITTING MACHINES Ernest Start, Wilford, Nottingham, England, assignor to William Cotton Limited Application April 24, 1953, Serial No. 350,846

Claims priority, application Great Britain June 23, 1952 8 Claims. (Cl. 66-110) This invention is for improvements in or relating to straight bar knitting machines and is particularly concerned with the jacks that are usually employed as a medium through which jack sinkers are operated in an advancing direction from a slurcock. More specifically these jacks usually consist of strip or plate upright members pivoted at their lower ends and having a forwardly projecting part or head at their upper ends for engaging the rear edges of the jack sinkers. For knitting without fashioning, the jack sinkers are partly retracted by a catch bar thereby retracting the jacks from a forward position to a position (hereinafter termed an intermediate position) which is intermediate the forward position and a rearward position in which they would be in engagement with a back stop, and for fashioning, the jack sinkers are fully retracted thereby fully retracting the jacks to said back stop after which the jack sinkers are partly advanced to the same intermediate position as for knitting leaving the jacks against the back stop. For moving the jack sinkers in the forward direction, the slurcock is reciprocable along the line of jacks at the rear, and it usually has leading and trailing concave faces which (in turn) engage the jacks successively and effect rapid forward acceleration of the jacks thereby advancing the jack sinkers. It is known to employ jack springs operated to act on the jacks for controlling them, but it has been found that whether or not these jack springs are employed, comparatively wide gaps occur between co-operating edges of at least some jacks and jack sinkers at such a time that when the slurcock is operated to effect the rapid forward acceleration of the jacks, the jack edges strike the jack sinker edges with appreciable force. This force is often such that the jack sinkers are thrown forwardly instead of being desirably advanced steadily, with the disadvantage that there is undue wear on said edges of the jacks and jack sinkers and there is a tendency for the yarn to be cut by the projected jack sinkers particularly when delicate yarns are employed such as those having either a short staple or smooth fibres.

The object of the invention is to minimise wear on the jacks and jack sinkers and effect a smoother opera tion of the jack sinkers than heretofore.

The invention provides, for a straight bar knitting machine, jack control mechanism constructed and arranged for pro-determined acceleration of the jacks and jack sinkers from a rest position of the jacks substantially in contact with the jack sinkers. Preferably the mechanism is constructed and arranged for substantially uniform acceleration of the jacks from the rest posi tion, and it may include locating means for positively locating the jacks substantially in contact with the jack sinkers before the latters advancement, so as to locate the jacks for advancement by jack engaging edges of a slurcock which are suitable for imparting the substantially uniform acceleration to thejacks. Said mechanism may include inter-engageable parts of the jacks and jack springs, and means for operating the jack springs to locate them with said parts co-operating thereby to locate the jacks substantially in contact with the jack sinkers before the latters' advancement by the jacks. The mechanism will generally be such as to allow falling back of the jacks after retraction of the jack sinkers, and for then advancing the jack springs to locate the jacks substantially in contact with the jack sinkers.

More specifically the mechanism may comprise interengageable parts of the jacks and jack springs for the desired location of the jacks, cam operating mechanism comprising knitting and fashioning cams on the main cam shaft for moving the jack springs between forward operative and rearward inoperative positions and suitable truck arm or lever mechanism between the cams and the jack springs, shogging means for changing control from one cam to the other, and a slurcock having suitably shaped edges for engaging the jacks to advance them and the jack sinkers with pre-determined acceleration from said location of the jacks.

The inter-engageable parts may consist of at least one step, abutment, flat or the like locating part of the jacks, and, for registering therewith, bent over ends of the jack springs, and the arrangement being such that when. the parts are in operative engagement, any force on the jack springs from the jacks tending to retract is in a direction axially of the springs. There may be a plurality of said locating parts on the jacks for alternative engagement by said jack spring ends to locate the jacks in any of a plurality of desired alternative positions (e.g. including a fully forward position) and said part or parts may be on an upwardly and rearwardly directed tail part of the jacks (which latter are substantially upright and are pivoted at their lower ends in use).

The slurcock for operating on the jacks conveniently has its concave parts made comparatively shallow and is formed with inclined faces leading to the concave parts.

The invention also provides mechanism as above employedin the machine.

The above and other features of the invention set out in the appended claims are incorporated in the constructions which will now be described, as specific embodiments with reference to the accompanying drawings in which:

Figure l is a general sectional view of relevant parts of a straight bar knitting machine according to the invention.

Figure 2 is an enlarged view of part of Figure 1 at one stage during knitting.

Figure 3 is a similar view of another stage during knitting.

Figure 4 is a similar view at a fashioning stage.

Figure 5 is a detail view of part of a modified slurcock.

Referring now to Figure l of the drawings, jack sinkers 1 are illustrated of the conventionaltype in a Cottons patent straight bar machine, said sinkers being mounted to slide in conventional manner in tricked sinker beds 2 mounted on the framework 3 of the machine. For sliding the jack sinkers, jacks 4 are provided pivoted at their lower ends 5 and having forwardly projecting upper heads 6 and rearwardly and upwardly projecting lower tails 7, and the jacks are adapted for appropriate pivotal movement in conventional manner by a slurcock S. The tails 7 of the jacks are stepped to form an upper abutment 9 and a lower abutment 10, the abutment 9 having a flat or cam face 11 and the abutment 10 having a flat face 12, for engagement respectively at different times by a bent'over free end 13 of jack springs 14. The jack springs 14 are carried by a mounting bar or bed 15 at their lower ends and this bed 15 is movable through the medium of an arm 29 which is rockable by a truck lever 16 pivoted at 17 and having a truck 18 which is biassed by a spring 28 on to either of two cams, a knitting cam 19 or a fashioning cam 30 on the main cam shaft 20, the cams being selected by shogging in known manner. Each part has an intermediate level A parts of which coincide for shogging from one to the other, the knitting cam 19 has a high part B and the fashioning cam 30 has a low part C. The slurcock 8 conveniently has each operative face formed of a shallow arcuate or concave part 21, 22 and a lead-in slightly inclined part 23, 24 as shown in Figure 5.

In operation and when the jack sinkers 1 have been advanced by the action of the slurcock 8 on the jacks 4 as shown in Figures 1 and 2, the jacks 4 are maintained with their heads 6 in contact with the rear edges 25 of the jack sinkers 1 by the bent free ends 13 of the jack springs 14 engaging the lower flat faces 12 of the abutments of the tails 7 of the jacks 4 (the springs being so disposed by the high part B on the knitting cam 19). Although not as shown in the drawings, the attitude of the spring assembly is such that the arm 29 tends to rotate clockwise (when viewing the drawings) under the action of gravity, Immediately prior to the jack sinkers being retracted by the catch bar (an intermediate position for knitting) as shown in Figure 3, the jack springs are moved rearwardly by said rotation of arm 29 under the action of gravity when the truck 18 is on the intermediate part A of cam 19 to such an extent that when the jacks 4 are moved rearwardly about their pivots 5 so as to lower the free ends of the tails 7 of the jacks, the bent free ends 13 of the jack springs 14 become engaged by the flat faces 11 of the upper abutments 9 of the. tails of the jacks (the springs being thereafter maintained in this position by the intermediate level A of the knitting cam 19) against the gravity bias on the arm 29; thus the jack springs form a jack spring stop and temporarily but precisely locate the jacks with the heads 6 thereof in contact or nearly in contact. with the rear edges of the jack sinkers 1.

When transferring is taking place during fashioning the jack springs 14 are moved back out of engagement with the jacks 4 (by gravity when the low part C of the fashioning cam is operative to allow the necessary full retraction of the jack sinkers 1 as shown in Figure 4; for this fashioning phase the jack sinkers are operated by the catch bar and during this operation the jacks are moved by the jack sinkers into engagement with a fixed back stop 26; the jacks remain thus whilst the jack sinkers are made to carry out their remaining fashioning motions by the catch bar. On completion of the fashioning cycle, the jack sinkers are left by the catch bar at their intermediate position (Figure 3) ready for the next advancement of the slurcock and at this time the knitting cam takes over from the fashioning cam such that the jack springs are advanced up to the jacks (by intermediate part A of cam 19) thereby to locate them substantially up to the jack sinkers in the intermediate position as before.

It will be understood from the above that the jack heads 6 are at all times maintained near to or in contact with the rear edges of the jack sinkers 1 during the drawing of each knitted course.

When the slurcock (shown in Figure 5) is used, a minimum of violence is applied to the yarn because the jacks, being positively located in the intermediate position substantially in contact with the jack sinkers before the movement of the slurcock will engage first a lead-in portion to the concave parts of the slurcock which is slightly inclined to the line of jacks (as distinct from at least some of the jacks first engaging an intermediate portion of a steep concave part indicated in broken lines of the slurcock as before), the curve of the concave part being such that the jacks will then be uniformly accelerated from the rest condition in the retracted position to their maximum speed, at which point the sinkers are arrested by the conventional forward stop or falling bar 27.

Should for any reason any of the jacks not be correctly located in the intermediate position by the jack springs, then they will of course be advanced initially by the inclined parts 23, 24 of the slurcock, It is to be understood that other means than the cam controlled jack springs cooperating with a step in the jacks may be employed for obtaining the equivalent control of the jacks, such for example as an extension of the catch bar, or a separate catch bar mechanism, for acting on the jacks.

What I claim is:

1. In a Cottons patent or other straight bar knitting machine having jack sinkers and a row of jacks therefor movable forwardly and rearwardly behind the jack sinkers and between extreme limits, the combination of abutment means on the jacks, movable stop means operable to engage behind said abutment means and positively locate the jacks in a position intermediate said extreme limits, means for operating the movable stop means, a slurcock movable behind the jacks along the row thereof, and forward shallow concave jack-engaging edges on the slurcock which are in such. relation to said intermediate position that, when the slurcock moves along the jacks positively located by the stop means in said intermediate position, the jacks are substantially uniformly accelerated by the slurcock from rest. I

2. In a Cottons patent or other straight bar knitting machine having jack sinkers and a row of jacks therefor movable forwardly and rearwardly behind the jack sinkers and between extreme limits, the combination of abutment means on the jacks, movable stop means operable to engage behind said abutment means and positively locate the jacks in a position intermediate said extreme limits, cam operated means for operating the movable stop means, a slurcock movable behind the jacks along the row thereof, and forward shallow concave jack-engaging edges on the slurcock which are in such relation to said intermediate position that, when the slurcock moves along the jacks positively located by the stop means in said intermediate position, the jacks are substantially uniformly accelerated by the slurcock from rest.

3. In a Cottons patent or other straight bar knitting machine having jack sinkers and a row of jacks therefor movable forwardly and rearwardly behind the jack sinkers and between extreme limits, the combination of rear abutment means on the jacks, a movable jack spring unit operable to butt against said rear abutment means on the jacks to positively locate the jacks in a position intermedi ate said extreme limits, cam operated means for operating the movable jack spring unit, a slurcock movable behind the jacks along the rowthereof, and forward shallow concave jack-engaging edges on the slurcock which are in such relation to said intermediate position that, when the slurcock moves along the jacks positively located by the jack spring unit butting against said abutment means on the jacks in said intermediate position, the jacks are substantially uniformly accelerated by the slurcock from rest.

4. In a Cottons patent or other straight bar knitting machine having jack sinkers and a row of jacks therefor movable forwardly and rearwardly behind the jack sinkers and between extreme limits, the combination of a step formation on the jacks providing alternative abutment loeating surfaces, a movable jack spring unit operable to alternatively butt against said abutment locating surfaces to positively locate the jacks alternatively in their extreme forward limit position and a position intermediate the extreme limits, a slurcock movable behind the jacks along the row thereof, cam operated means for operating the jack spring unit including causing the latter to butt against that abutment locating surface, by which the jacks are positively located in the intermediate position, when the slurcock is operated, and forward shallow concave jackengaging edges on the slurcock which are in such relation to said intermediate position that, when the slurcock is operated, the jacks are substantially uniformly accelerated by the slurcock from rest.

5. In a Cottons patent or other straight bar knitting machine having jack sinkers and a row of jacks therefor movable forwardly and rearwardly behind the jack sinkers and between extreme limits, the combination of a step formation on the jacks providing alternative abutment loeating surfaces, a movable jack spring unit operable to alternatively butt against said abutment locating surfaces to positively locate the jacks alternatively in their extreme forward limit position and a position intermediate said extreme limits, a slurcock movable behind the jacks along the row thereof, cam operated means for operating the jack spring unit including one cam for causing it to be disposed in one position clear of the jacks when the jacks are in their extreme rearward limit position for fashioning, and a second cam for causing the jack spring unit to be disposed in alternative positions butting against one or the other of said abutment located surfaces of the jacks including butting against that abutment locating surface, by which the jacks are positively located in the intermediate position, when the slurcock operates, and forward shallow concave jack-engaging edges on the slurcock which are in such relation to said intermediate position that, when the slurcock operates, the jacks are substantially uniformly accelerated by the slurcock from rest.

6. In a Cottons patent or other straight bar knitting machine having jack sinkers and a row of jacks therefor movable forwardly or rearwardly behind the jack sinkers and between extreme limits, the combination of abutment means on the jacks, movable stop means operable to engage behind said abutment means and positively locate the jacks in a position intermediate said extreme limits, means for operating the movable stop means, a slurcock movable behind the jacks along the row thereof, forward shallow concave jack-engaging edges on the slurcock which are in such relation to said intermediate position that, when the slurcock moves along the jacks positively located by the stop means in said intermediate position, the jacks are substantially uniformly accelerated by the slurcock from rest, and said slurcock having lead-in jack engaging edges leading to the shallow concave edges and which are slightly inclined to the row of jacks for engagement by the jacks before they engage the shallow concave edges.

7. In a Cottons patent or other straight bar knitting machine having jack sinkers, and a row of jacks therefor pivotally movable forwardly and rearwarly behind the jack sinkers and between extreme limits, the combination of heads on said jacks engaging the sinkers, rearwardly directed tails on said jacks, a step formation on said tails providing alternative flat abutment locating surfaces at different distances from the jack head, a movable jack spring unit operable behind the jacks and having a flat free end face to abut against said flat abutment locating surfaces alternatively and positively locate the jacks alternatively in their extreme forward limit position and a position intermediate the extreme limits, a slurcock movable behind the jacks along the row thereof, cam operated means operable on the jack spring unit for causing the latter to be disposed in position with its flat free end face abutting against one or other of the flat abutment locating surfaces on the jacks at required times including abutting against that flat abutment locating surface, by which the jacks are positively located in the intermediate position, when the slurcock is operated, and forward shallow concave edges on the slurcock which are in such relation to said intermediate position that, when the slurcock operates, the jacks are substantially uniformly accelerated by the slu rcock from rest.

8. In a Cottons patent or other straight bar knitting machine having jack sinkers, and a row of jack therefor pivotally movable forwardly and rearwardly behind the jack sinkers and between extreme limits, the combination of heads on said jacks engaging the sinkers, rearwardly directed tails on the jacks, a step formation on the tails providing alternative fiat abutment locating surfaces at different distances from the jack heads, a movable jack spring unit operable behind the jacks and having a fiat free end face to engage said flat abutment locating surfaces alternatively and positively locate the jacks alternatively in their extreme forward limit position and a position intermediate the extreme limits, a slurcock movable behind the jacks along the row thereof, cam operated means for operating the jack spring unit including one cam for causing the jack spring unit to be disposed in one position clear of the jacks when the jacks are in their extreme rearward limit position for fashioning, and a second cam for causing the jack spring unit to be disposed in alternative positions with its flat free end face abutting against one or other of the flat abutment locating surfaces of the jacks at required times including abutting against that fiat abutment locating surface, by which jacks are positively located in the intermediate position, when the slurcock is operated, forward shallow concave jack-engaging edges on the slurcock which are in such relation to said intermediate position then, when the slurcock operates, the jacks are substantially uniformly accelerated by the slurcock from rest, and said slurcock having lead-in jack-engaging edges leading to the shallow concave edges and which are slightly inclined to the row of jacks for engagement by jacks before they engage the shallow concave edges.

References Cited in the file of this patent UNITED STATES PATENTS 2,317,417 Suess Apr. 27, 1943 2,473,355 Berger et al. June 14, 1949 2,580,620 Vaclavik Jan. 1, 1952 FOREIGN PATENTS 592,450 Germany Feb. 7, 1934 970,182 France June 7, 1950 

